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Browser - An application program that provides a way to look at
and interact with all the information on the World Wide Web or
PC. The word “browser” seems to have originated prior to the
Web as a generic term for user interfaces that let you browse text
files online.
Cable Modem – A device that connects a computer to the cable
television network, which in turn connects to the Internet. Once
connected, cable modem users have a continuous connection to
the Internet. Cable modems feature asymmetric transfer rates:
around 36 Mbps downstream (from the Internet to the computer),
and from 200 Kbps to 2 Mbps upstream (from the computer to
the Internet).
Data Packet - One frame in a packet-switched message. Most
data communication is based on dividing the transmitted
message into packets.
For example, an Ethernet packet can be from 64 to 1518 bytes in
length.
Default Gateway - The routing device used to forward all traffic
that is not addressed to a station within the local subnet.
DHCP (Dynamic Host Configuration Protocol) - A protocol that
lets network administrators centrally manage and automate the
assignment of Internet Protocol (IP) addresses in an
organization’s network. Using the Internet’s set of protocol
(TCP/IP), each machine that can connect to the Internet needs a
unique IP address. When an organization sets up its computer
users with a connection to the Internet, an IP address must be
assigned to each machine. Without DHCP, the IP address
must be entered manually at each computer and, if computers
move to another location in another part of the network, a new IP
address must be entered. DHCP lets a network administrator
supervise and distribute IP addresses from a central point and
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automatically sends a new IP address when a computer is
plugged into a different place in the network.
DHCP uses the concept of a “lease” or amount of time that a
given IP address will be valid for a computer. The lease time
can vary depending on how long a user is likely to require the
Internet connection at a particular location. It’s especially useful
in education and other environments where users change
frequently. Using very short leases, DHCP can dynamically
reconfigure networks in which there are more computers than
there are available IP addresses.
DHCP supports static addresses for computers containing Web
servers that need a permanent IP address.
DNS - The Domain Name System (DNS) is the way that Internet
domain names are located and translated into an Internet
Protocol (IP) address. A domain name is a meaningful and
easy-to-remember “handle” for an Internet address.
Domain - A sub network comprised of a group of clients and
servers under the control of one security database. Dividing
LANs into domains improves performance and security.
Download - To receive a file transmitted over a network. In a
communications session, download means receive, and upload
means transmit.
Driver - A software module that provides an interface between a
network interface card and the upper-layer protocol software
running in the computer; it is designed for a specific adapter, and
is installed during the setup of the adapter.
DSSS (Direct-Sequence Spread-Spectrum) - DSSS generates a
redundant bit pattern for each bit transmitted. This bit pattern is
called a chip (or chipping code). The longer the chip, the